Radio communication apparatus, radio communication system, and method of expanding terminal for use in radio communication system

ABSTRACT

A radio communication system has a terminal which enables radio communication through a base station, and service condition of a radio communication terminal to register is registered together when the radio communication terminal is registered.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a radio communication system and amethod of expanding a terminal with respect to a base station of theradio communication system.

2. Description of the Related Art

Presently, there is a radio communication system capable ofcommunicating with remote terminals through a base station connected toa communication network. An example of this communication system is aPHS (Personal Handyphone System) which is to be put into practice inJapan. The specification of the PHS is standardized in RCR STD-28. ThePHS has a base station installed in an indoor space (e.g., a house or anoffice) or in an outdoor space (e.g., a public space). Each of theindoor and outdoor base stations can be connected to terminals throughradio communication.

Further, the standard defines transceiver communication by which directconversation can be made between terminals of like transceivers.Transceiver communication is allowed for only those terminals which havethe same base identification information (in particular, indoorterminals).

SUMMARY OF THE INVENTION

An object of the present invention is, therefore, to provide a radiocommunication apparatus, a radio communication system, and a method ofexpanding a terminal for use in the radio communication system, whichare more convenient than conventional systems and methods.

In order to solve the above problems, according to an aspect of thepresent invention, there is provided a method of installing a newterminal in a radio communication system having a base station and aterminal, the method comprising the steps of: registering servicecondition together with base station identification data into theterminals; and registering service condition together with terminalidentification data into the base station.

According to another aspect of the present invention, there is provideda method of causing a base station to conduct in when a new terminal isinstalled in a radio communication system having a base station and aterminal, the method comprising the steps of: comparing recitation datasupplied from the new terminal with recitation data of the base stationitself, and storing service condition of the new terminal on conditionthat the recitation data from the new terminal comply with therecitation data of the base station; and comparing contents of aconnection request inputted from the new terminal with the servicecondition stored in the memory means, and controlling connection of thenew terminal on the basis of comparison results.

According to still another aspect of the present invention, there isprovided a radio communication system having a base station and aterminal, capable of installing a new terminal, the base stationcomprising: means for storing service condition of the new terminal;means for comparing contents of a connection request inputted from thenew terminal with the service condition stored in the storing means; andmeans for controlling transmission connection of the new terminal, onthe basis of comparison results of the comparing means.

According to still another aspect of the present invention, there isprovided a radio communication system having a base station and aterminal, capable of installing a new terminal, the base stationcomprising: first comparing means for comparing recitation data suppliedfrom the new terminal with recitation data of the base station itself;means for storing service condition of the new terminal on conditionthat the recitation data of the new terminal complies with therecitation data of the base station; second comparing means forcomparing contents of a connection request inputted from the newterminal with service condition stored in the storing means; and meansfor controlling connection of the new terminal on the basis ofcomparison results of the second comparison means.

According to still another aspect of the present invention, there isprovided a method of installing a new terminal in a radio communicationsystem having a base station and a terminal, the method comprising thesteps of: transmitting a system code of the base station stored in theterminal from a terminal which has already been registered into the basestation; and receiving the system code of the base station transmittedfrom the terminal which has already been registered in the base stationby the new terminal and registering it in the new terminal.

According to still another aspect of the present invention, there isprovided a radio communication system having a base station and aterminal, the base station comprising: first storing means for storing adummy system code; and means for transmitting a dummy system code storedin the memory means to a terminal; and the terminal comprising; meansfor receiving a dummy system code transmitted from the transmissionmeans of the base station; and second storing means for storing thedummy system code received by the receiving means.

According to still another aspect of the present invention, there isprovided a radio communication apparatus for making radio communicationwith a base station, comprising a memory arranged to be capable of beingdetachably attached to the radio communication apparatus and storing adummy system code, and direct communication with another radiocommunication apparatus is made on the basis of the dummy system codestored in the memory when the memory is attached to the radiocommunication apparatus.

In the present invention, even if terminals previously have the samebase station identification information, transceiver communication canbe achieved.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe invention, and together with the general description given above andthe detailed description of the preferred embodiments given below, serveto explain the principles of the invention.

FIG. 1 is a diagram showing a connection state where a radiocommunication system according to a first embodiment of the presentinvention is used;

FIG. 2 is a sketch drawing showing an indoor base station in the radiocommunication system according to the first embodiment;

FIG. 3 is a sketch drawing showing a radio communication terminal in theradio communication system according to the first embodiment;

FIG. 4 is a block diagram showing the circuit configuration of an indoorbase station in the radio communication system according to the firstembodiment;

FIG. 5 is a block diagram showing the circuit configuration of a radiocommunication terminal in the radio communication system according tothe first embodiment;

FIG. 6 is a figure showing a memory structure of a terminal data memoryused in an indoor base station;

FIG. 7 is a figure showing a memory structure of a registered conditionmemory;

FIG. 8 is a flow chart showing a procedure for radio communicationterminal registration in the radio communication system according to thefirst embodiment;

FIG. 9 is a figure showing the structure of an identification data usedin communication between a base station and a personal station;

FIG. 10 is a flow chart showing a procedure for transmission from aradio communication terminal in the radio communication system accordingto the first embodiment;

FIG. 11 is a figure showing the structure of identification data whentransceiver communication is performed;

FIG. 12 is a flow chart showing a procedure for deleting a registrationdata in the radio communication system according to the firstembodiment;

FIG. 13 is a flow chart showing another procedure for deleting aregistration data in the radio communication system according to thefirst embodiment;

FIG. 14 is a flow chart showing further another procedure for deleting aregistration data in the radio communication system according to thefirst embodiment;

FIG. 15 is a flow chart showing a procedure for registering a dummy ID,according to a second embodiment of the present invention;

FIG. 16 is a block diagram showing the circuit configuration of a radiocommunication terminal used for another method of registering a dummy IDaccording to the second embodiment;

FIG. 17 is a figure explaining the concept of another method forregistering a dummy ID according to the second embodiment; and

FIG. 18 is a flow chart showing a registration procedure of anotherembodiment according to the first embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be explained hereinafter withreference to the drawings. With respect to the following embodiments,explanation will be directed to examples applied to a PHS (PersonalHandyphone System) which is considered to be put into practice in Japan.This PHS has a radio base station (which will be referred to as a basestation) provided at an indoor space and a radio personal stationconnected thereto by radio communication. Further, the PHS ischaracterized in that the radio personal station is linked with a publicradio base station (which will be referred to as a cell station). Inaddition, if radio personal stations have identification data of thesame base station, the radio personal stations can communicate with eachother without passing through the base station.

EMBODIMENT 1

FIG. 1 shows a schematic structure where a plurality of radio personalstations (which will be referred to as personal stations, hereinafter)are used in a first embodiment. In FIG. 1, reference T1 denotes a radiocommunication set. The radio communication set T1, for example, includesone base station (BS) A1 and two personal stations (PS) B1 and B2.Further, the base station A1 is connected to a communication networkthrough a communication line L. PSTN, ISDN, or the like is known as thecommunication network.

Meanwhile, another radio communication set T2 is connected to thecommunication network through the communication line as in the samemanner as above. This radio communication set T2, for example, has onebase station C1 and two terminals D1 and D2.

Further, when communication is made from a terminal B1 or B2 to anotherterminal connected to a communication network, the identification number(e.g., telephone number) of a party to communicate is sent to thecommunication network, to call the party. When a personal station of aparty receives a call signal from a terminal of another party through abase station A1, the personal station responds to the call signal,thereby enabling communication. In the same way, when communication ismade between the terminals D1 and D2 in the radio communication set T2,communication is made through the base station C1.

Furthermore, when communication is made between personal stations, theremay be both cases where the communication is made through a base stationand where the communication is directly made between the personalstations. For example, in the radio communication set T1, whencommunication is made between personal stations through a base stationA1, a party calls another personal station B1 (or B2) from a personalstation B2 (or B1) through the base station A1, and the former personalstation responds to this call. In addition, when direct communication ismade between personal stations without relaying the base station, apredetermined frequency assigned to direction communication is used tocall, from one of the personal stations, to another thereof on thecondition that each personal station has identification data of the samebase station, and direct communication is started when the anotherpersonal station responds to this call.

FIG. 2 is a sketch drawing of the base station A1 (C1). The base stationA1 is connected to a communication network through a communication line,and power is supplied through an outlet. Reference numeral 7 denotes anantenna used to communicate a personal station. Reference numeral 11adenotes a display of a display unit 11 for displaying variousinformation. The display 11a displays, for example, input guidances in aregistration mode. Reference 8a denotes a function key used whenoperation is switched into various modes, and reference 8b denotes asetting key for indicating setting of data. Reference 8c denotes adelete key for ordering deletion of data, and reference 8d denotesnumerical keys for inputting memory numbers and terminal numbers.

FIG. 3 is a sketch drawing of a personal station B1 (which is the sametype as the personal stations B2, D1, and D2). Reference 29 denotes anantenna for transmitting/receiving a radio wave. Reference 26 denotes aspeaker for outputting sounds. Reference 27 denotes a microphone fortaking-in sounds. Reference 33a denotes a display for displaying variousdata. Reference 30a denotes an off-hook key which orders receipt andtransmission, and reference 30b denotes an on-hook key for ordering abreak of communication. Reference 30c denotes a transceiver key forordering extension communication or transceiver communication, andreference 30d denotes a reservation key for indicating a reservation ofcommunication.

Further, reference 30e denotes a telephone directory key by whichoperation is switched into a mode for searching telephone directory datastored in the apparatus, and reference 30f denotes a mode key forordering various modes. Reference 30g denotes a re-dial key forre-dialing a telephone number which has been dialed before, with onlyone key. Reference 30h denotes a set key for setting various data.Reference 30i denotes a deletion key for deleting data, and reference30j denoted a switching key used for a so-called catch phone. References30k and 30l denote keys for instructing scroll of data and an increaseor decrease in sound volume, and reference 30m denote dial keys andalphabet keys.

FIG. 4 shows a block structure of a base station A1 (C1) in the radiocommunication set T1 (T2). In FIG. 4, reference 1 denotes a CPU 1, andthis CPU 1 is connected with a communication procedure processing unit(which will be referred to as a CPPU hereinafter) 2 which is used forperforming control when communication with personal stations B1 and/orB2 is made.

The CPU1 uses a RAM1b to perform the entire operation control of thebase station A1 on the basis of programs in the ROM1a, and performsfirst and second collation processing, memory processing and connectioncontrol processing. For example, when a personal station D1 of adifferent radio communication set T2 is registered in the base stationA1, cipher data supplied from the personal station D1 of the differentradio communication set T2 is checked with cipher data of itself (e.g.,the first check processing). When cipher data of the personal station D1complies with cipher data of itself by this check processing, theservice condition of the personal station D1 will be stored into theterminal data memory 9 which will be described below.

Further, when transmission is made from a personal station through thebase station A1, request of transmission (e.g., outside lines andextensions lines) inputted from the personal station are checked withregistration condition stored in the terminal data memory 9 (e.g., thesecond check processing). On the basis of checking results, transmissionconnections and the likes are controlled.

The CPPU 2 is connected with a speech codec 3 and a radio unit 6. Theradio unit 6 is connected with an antenna 7. The radio unit 6 modulatesand demodulates signals transmitted to and received from a personalstation through the antenna 7, and frequency conversion and burstcontrol are performed on the basis of control signals from the CPU 1.The CPPU 2 performs TDMA (Time Division Multiple Access) processing.Specifically, control signals or sound signals are extracted atpredetermined timings from receive signals from the radio unit 6. Inaddition, sound signals from the speech codec 3 or the CPU 1 areinserted into transmission signals at predetermined timings, and areoutputted to the radio unit 6. Further, connection/disconnection of aradio communication line is performed under control of the CPU1.

The speech codec 3 is connected with a PCM codec 4. A network interface5 is connected through the PCM codec 4, and a communication line isconnected to a network interface 5. The speech codec 3 performscompression/extension processing of digital data. Specifically, whendata from a personal station is received, ADPCM sound signals (e.g.,compressed sound signals) sent from the CPPU 2 are decoded (extended)and PCM sound signals are outputted to the PCM codec 4. In addition,when signals are sent to a personal station, PCM sound signals sent fromthe PCM codec 4 are encoded (compressed) and ADPCM sound signals areoutputted to the CPPU 2.

In the PCM codec 4, analogue/digital conversion processing is performed.That is, when signals from the personal station are received, PCM soundsignals are subjected to digital/analogue conversion and are outputtedto the network interface 5. In addition, when signals are transmitted tothe personal station, analogue sound signals are analogue/digitalconverted and PCM sound signals are outputted to the speech codec 3.

The network interface 5 comprises a signal arrival detection circuit, adial pulse control circuit, a speech network, a DTMF signal generatorcircuit, and the like. The network interface 5 is connected to aconnection line, like a normal telephone, and control such as detectionof an arrival of a signal, dial transmission, communication, and thelike is performed. That is, when signals are received through acommunication line, a connection state (line connection/linedisconnection) is controlled on the basis of control signals from theCPU 1, and when a line is connected thereby enabling a communicationstate, analogue sound signals inputted through the communication lineare sent to the PCM codec 4, and simultaneously, analogue sound signalsare outputted through the communication line.

Meanwhile, the CPU 1 is connected with a key input unit 8, a terminaldata memory 9, an ID memory 10, a display unit 11, and a ringer 12, inaddition to the CPPU 2 stated above.

The key input unit 8 is used when expansion of a personal station isset.

Data concerning a terminal number and identification data (PS-ID) of apersonal station additionally attached to the base station A1 and dataconcerning the terminal condition (e.g., F1 to F4 which will bedescribed later) and the likes of the additionally attached personalstation are stored into a terminal data memory 9. Specifically, as shownin FIG. 6, terminal numbers, PS-IDs, and terminal condition of thepersonal stations (B1 and B2) registered in the base station A1 as wellas identification data (CS-ID=SYS-ID+SUB-ID) of the base station A1 arestored into the ID memory 10. In this embodiment, although the terminaldata memory 9 and the ID memory 10 are constructed independently fromeach other, they may be formed of one memory.

In the display unit 11, a cipher number, a terminal number, and thelikes inputted from the key input unit 8 are displayed on the displayunit 11 when expansion of a terminal is set, and the display unit 11comprises a display 11a, a driving circuit, and the likes. A ringer 12generates a sound notifying arrival of a signal when the signal arrivaldetection circuit of the network interface 5 detects an arrival of asignal from an external device.

In addition, the power supply unit 13 is connected to an outlet, andsupplies power to respective sections.

FIG. 5 is a diagram showing the block structure of a terminal B1 (B2,D1, D2) in the radio communication set T1 (T2). In FIG. 5, referencenumeral 21 denotes a CPU which uses a RAM 21b on the basis of programsin the ROM 21a to perform the entire operation control. The CPU 21 isconnected with a communication procedure processing unit (which will bereferred to as a CPPU) used when control of communication with a basestation is performed. In addition, the CPU 21 has a timer 21c and countsfor a predetermined time period. The CPU 21 is connected with a timekeeper 21d for calculating date and hour.

The CPPU 22 is connected with a speech codec 23 and a radio unit 28.This radio unit 28 is connected with an antenna 29, and performsfrequency conversion, modulation, and demodulation on signalstransmitted and received through an antenna 29.

The speech codec 23 is connected with an AMP 25 through a PCM codec 24,and the AMP 25 is connected with a speaker 26 and a microphone 27. Thespeech codec 23 performs compression/extension processing. When signalsfrom the base station A1 are received, the speech codec 23 demodulates(or extends) ADPCM sound signals sent from the CPPU 22 into PCM soundsignals. Further, when signals are transmitted to the base station A1,PCM sound signals sent from the PCM codec 24 are encoded (or compressed)into ADPCM sound signals and are outputted to the CPPU 22.

The PCM codec 24 performs analogue/digital conversion processing. Whensignals from the base station are received, PCM sound signals sent fromthe speech codec 23 are digital/analogue converted and then outputted.The analogue sound signals thus outputted are amplified by the AMP 25,and are then outputted from the speaker 26. In addition, when signalsare transmitted to the base station, the analogue sound signals inputtedfrom the microphone 7 are amplified by the AMP 25 and are outputted tothe speech codec 23 after being analogue/digital converted by the PCMcodec 24.

Meanwhile, the CPU 21 is connected with a key input unit 30, aregistered condition memory 31, an ID memory 32, a display unit 33 and aringer 34, in addition to the CPU 22 stated above.

The key input unit 30 has a function key, a dial key, and anon-hook/off-hook key (see references 30a to 30m in FIG. 3), and is usedto input a telephone number of an opposite party and to set expansion ofa terminal.

Data concerning a personal station additionally installed is stored inthe registered condition memory 31. Specifically, as shown in FIG. 7,the registered condition memory 31 stores identification data of a basestation (CS-ID=SYS-ID+SUB-ID), a terminal number of a terminal, terminalcondition (i.e., F1 to F4 which will be described later), and terminalnumbers (i.e., group terminal numbers) of other terminals which belongto a CS-ID. Further, the ID memory 32 stores identification data (PS-ID)of a previously registered personal station B1 itself and identificationdata (CS-ID=SYS-ID+SUB-ID) of previously depending base station A1. Inaddition, in this embodiment, although a registered condition memory 31and an ID memory 32 are constructed independently from each other, thesememories may be formed by one memory.

The display unit 33 displays a cipher number and a terminal number whichare inputted from a key input unit 30 when the display unit 33 setsexpansion of a terminal, and a telephone number of an opposite party.The ringer 34 generates a signal arrival sound upon receipt of a callsignal from the base station A1.

The power supply unit 35 internally includes a secondary battery andsupplies power to respective portions. This power supply unit 35 isconnected with a charge unit 36 for charging the secondary battery. Inaddition, the power supply unit 35 includes an attach/detach detectingcircuit 35a for detecting attachment or detachment of the charge unit36, and outputs an attach/detach detection signal S1 therefrom to a CPU21.

Further, the circuit configurations of the base station C1 and personalstation D1 of the radio communication set T2 are the same as those shownin FIGS. 4 and 5, and explanation thereof will be omitted herefrom.

Registration Operation

In the next, operation of the radio communication set constructed asshown in the above will be explained with reference to flow charts shownin FIGS. 8 and 9. This embodiment shows a case where registration ismade into the base station A1 of the radio communication set T1 whilethe personal station D2 is kept depending on the base station C1 of theradio communication set T2.

At first, to make the personal station D2 of the radio communication setT2 depend on the base station A1 of the radio communication set T1, aprocedure of registration into the side of the base station A1 will beexplained on the basis of FIG. 8.

When a user performs registration into the base station A1, a functionkey 8a of a key input unit 8 is pressed down by the user so that thebase station A1 is set into a registration receive mode (step 101). Thedisplay 11a thereby displays an indication that the base station is in aregistration mode and simultaneously displays an indication suggestingan input of a cipher number. On the basis of the indications, the userinputs, for example, a cipher number of three figures by means of anumber key 8d of the key input unit 8, and then, the cipher number isstored into a RAM 1b of the base station A1 (step 102).

Further, the display 11a displays an indication suggesting an input ofthe terminal number of a personal station to be registered. The terminalnumber of the personal station D2 (e.g., the third personal station inthis embodiment) from the terminal numbers of the personal stationsbelonging to the base station A1 of the personal station D2 to beregistered is inputted and the terminal number thus inputted is storedinto a predetermined region of the terminal data memory 9 (refer to FIG.6) in a step 103.

In the next, a user makes selection from four functions, i.e., anoutside line function (flag F1) of transmitting signals to the outsidethrough the base station, an extension function (flag F2) of allowingpersonal stations to communicating with each other through the basestation, a transceiver function (flag F3) of allowing personal stationsto directly communicate with each other without passing through the basestation, and a remote control function (flag 4) of remote-controllinganother personal station or the base station itself through the basestation (refer to FIG. 6).

Further, functions which can be selected are not limited to the abovefour functions, but it is possible to make an arrangement such that aspecial receiving function can be selected.

At first, the CPU 1 displays, on the display unit 11, a message askingwhether or not use of an outside line communication function should bepermitted, thereby suggesting the user to set whether the outside linecommunication function should be permitted or inhibited. Upon detectionof a response which permits use of the function is received from theuser, i.e., when permission for the outside line communication isselected by a set key 8b of the key input unit 8 (step 104), a flag ismarked on the flag F1 of the terminal data memory 9 (step 105). When thesetting processing for permitting or inhibiting use of the outside linecommunication function is completed, the CPU 1 displays, on the displayunit 11, a message suggesting whether or not use of the extensioncommunication function should be permitted, thereby suggesting the userso as to perform setting a response to the message. When the CPU 1detects a response from a user which permits use of the function, i.e.,when permission for extension line communication is selected by the setkey 8b of the key input unit 8 (step 106), a flag is made so as to standon a flag F2 of the terminal data memory 9 (step 107).

In addition, the CPU 1 displays, on the display unit 11, a message as towhether use of a transceiver communication function should be permittedor not. When the CPU 1 detects a response from a user which permits useof the function, i.e., when permission for use of the transceivercommunication function is selected by the set key 8 of the key inputunit 8 (step 108), a flag is made so as to stand on a flag F3 of theterminal data memory 9 (step 109).

Further, the CPU 1 displays, on the display unit 11, a message as towhether use of an extension remote function should be permitted or not.When the CPU 1 detects a response from a user which permits use of thefunction, i.e., when permission for use of the extension remote functionis selected by the set key 8b of the key input unit 8 (step 110), a flagis made so as to stand on a flag F4 of the terminal data memory 9 (step111). In addition, when non permission is inputted by the deletion key8c of the key input unit 8 in each of the above steps 104,106,108, and110, the flag is not made so as to stand on the flag.

In this state, the operation mode changes into a stand-by mode where aregistration requirement is waited for.

Thereafter, an user performs registration operation in the side of thepersonal station D2.

At first, a user presses down a mode key 30f of the key input unit 30,thereby to bring the personal station into a registration receive mode(step 112). In this state, a message suggesting an input of the samecipher number as the cipher number inputted in the step 102 is displayedon the display 33a of the display unit 33. When the user inputs a ciphernumber of, for example, three figures by means of a dial key 30m of thekey input unit 30 in response to the display (step 113), the CPU 21writes the cipher number into registration request message data andsends the data to the base station A1 from an antenna 28 through a CPPU22 and a radio unit 28 (step 114). Normal message data is formed asidentification data consisting of a CS-ID (SYS-ID and SUB-ID) and aPS-ID, as shown in FIG. 9. However, the identification data in theregistration request data is transmitted with a cipher number beingwritten in an area of the CS-ID.

Further, when the CPU 1 in the base station A1 receives registrationrequest message data from the personal station D2 through the antenna 7,radio unit 6, and the CPPU 2 (step 115), the cipher number written inthe registration request message data thus received is extractedtherefrom, and the cipher number thus received is checked with thecipher number stored in the RAM 1b (step 116). In case where it is foundby the checking that both cipher numbers do not comply with each other,a procedure of registering the personal station D2 into the base stationA1 is completed.

On the other hand, when both the cipher numbers comply with each other,the following data is sent from the antenna 7 to the personal station D2through the CPPU 2 and the radio unit 6 (step 117).

1) CS-ID of the base station A1 stored in the ID memory 10

2) Terminal condition stored in the terminal data memory 9 in the abovesteps 104 to 111

3) Terminal number

4) Other terminal numbers (group terminal number) which belong to thebase station A1 and are stored in the terminal data memory 9 and in theID memory 10

Through the antenna 29, radio unit 28, and CPPU 22, the CPU 21 of thepersonal station D2 receives CS-ID, terminal condition, terminalnumbers, and group terminal numbers which are transmitted from the basestation A1 (step 118), and stores them into corresponding areas in theregistered condition memory 31, respectively. Further, the CPU 21 readsout a PS-ID of the personal station D2 itself, and transmits the PS-IDto the base station A1 (step 119).

Through the antenna 7, radio unit 6, and the CPPU 2, the CPU 1 of thebase station A1 receives the PS-ID, and stores the PS-ID into theterminal data memory 9 so as to comply with the terminal number and theterminal condition which has already been stored (step 120). Then, theCPU 1 transmits the terminal number of the personal station thusregistered, to another personal station which has already been belongingto the base station A1 (step 121). The another personal station storesthe terminal number registered in this way, into an area of theregistered condition memory 31 for group terminal numbers.

In this manner, operation for registering the personal station D2 intothe base station A1.

Transmission Operation

In the next, a procedure for outside line transmission from a personalstation in a radio communication set thus registered will be explainedwith reference to FIG. 10. In this case, transmission of an outside lineand an extension line from regular personal stations B1 and B2 in theradio communication set T1 is well known, and explanation thereof willtherefore be omitted herefrom.

FIG. 10 shows flow charts of operations in the base station A1 andpersonal station D2. Here, explanation will be made to a case wheretransmission of an outside line is performed through the base station A1by the personal station D2 of the radio communication set T2 whichbelongs to the base station A1 of the radio communication set T1 inaccordance with registration processing as stated above. Normally, onthe base of the CS-ID stored in the ID memory 32, the personal stationD2 is connected to a base station having the CS-ID. However, the presentcase relates to a case where the station D2 cannot be linked with thebase station having the CS-ID stored in the ID memory 32, but can belinked with the CS-ID stored in the registered condition memory 31.

At first, when an off-hook key 30a of the key input unit 30 of thepersonal station D2 is operated and an outside line transmission requestis generated (step 122), the PS-ID of the station D2 itself and theCS-ID of a designated base station A1 are respectively read out, fromthe ID memory 32 and the registered condition memory 31, with respect tothe base station A1 which currently receives control signals, and linkchannel formation request message data is prepared and transmitted (step123).

The base station A1 receives the link channel formation request messagedata (step 124) and checks the PS-ID in link channel formation requestmessage with the PS-ID registered in the terminal data memory 9 or IDmemory 10 (step 125). When it is determined in the step 125 that theregistration has been made, checking is made as to whether or not theflag F1 of the terminal condition registered with respect to the PS-ID(personal station D2) is permitted. When the terminal condition ispermitted in this step 126, the CPU 1 requests search of an empty slotwith respect to the CPPU 2 (step 127). When an empty slot exists, alink-channel assign message is sent to a personal station D2 so as tomove into the empty slot (step 129).

In addition, when both of the PS-IDs do not comply with each other,service condition are not permitted, or an empty slot does not exist inany of steps 125,126, and 127, a link channel denial message istransmitted (step 128).

The personal station D2 receives these messages (step 130) and if areceived message is a link channel assign message, normal outside linetransmission processing is performed. Specifically, the base station A1and the personal station D2 respectively control their own radio units 6and 28 so as to comply with an assigned empty slot, and simultaneously,an indication showing the outside line transmission enable state isoutputted to the display unit 33. In addition, a channel link is formedthereby forming a channel (steps 131 and 132), an audible soundnotifying the outside line transmission enable state (i.e., atransmission sound) is outputted from the speaker 26.

Further, when a dial number is inputted by a user through dial keys 30mof the key input unit 30 of the personal station D2, the dial number istransmitted to the base station A1 (step 133). When the base station A1receives the dial number and sends the number to a communication channelnetwork L through the network interface 5 (step 134). When an oppositeparty responds to the dial number by ON-hooking, communication can bestarted (steps 135 and 136). In addition, when a link channel assigndenial message is received in the step 130, outside line processing isnot carried out.

When communication is once started, sound signals of a user inputted bya microphone 27 of the personal station D2 are amplified by an AMP 25and analogue signals of the user are analogue/digital-converted in a PCMcodec 24. PCM sound signals thus converted are sent to a speech codec23, are compressed (or encoded) into ADPCM sound signals, and are thenoutputted to the CPPU 22. The ADPCM sound signals are formatted intocompressed sound signals in the CPPU 22 and are frequency-converted soas to have a modulated and assigned channel frequency. The signals arethen transmitted to the base station A1 from the antenna 29.

In the base station A1, communication signals received by the antenna 7are frequency-converted and demodulated so as to have a middle frequencyin the radio unit 6. In the CPPU 2, signals for one slot are extractedfrom the demodulated communication signals, and compressed sound signalsare outputted to the speech codec 3. These compressed sound signals areextended (modulated) in the speech codec 3 and the PCM sound signals aredigital/analogue-converted by the PCM codec 4, so that analogue soundsignals are outputted to a communication channel network L through thenetwork interface 5.

A procedure for transmission from the personal station D2 has beenexplained above, while a procedure for receiving signals in the personalstation D2 is executed in the order reversal to the order of the abovesteps, so that received sound signals are finally outputted as soundsfrom the speaker 26.

Note that although the above explanation has been made to an outsideline transmission of the personal station D2, the same operation asabove is performed for extension line transmission and extension lineremote transmission.

Supposing that the terminal condition of the personal station D2 permitsonly transceiver communication (i.e., permits only the flag F3), a linkchannel assign denial message is sent from the base station A1 in thestep 128. The personal station D2 receives the link channel assigndenial message and does not perform outside line transmission.

In addition, if outside line communication and extension linecommunication are designated when a new personal station is registeredin accordance with the registration procedure explained above (e.g.,when a personal station B3 is registered into the base station A1), useof the new personal station is denied except for other purposes than theoutside line communication and the extension line communication, and thenew personal station comprising only necessary functions can thus beregistered. (In this case, registration may be performed by replacing apersonal station D2 with a personal station B3 in the example explainedabove.)

Meanwhile, if the personal station D2 is once registered as permittingonly transceiver communication, transceiver communication is enabled bythe CS-ID since the CS-ID of the base station A1 is registered into thepersonal station D2. That is, when transceiver communication is madebetween a personal station B1 and a personal station D2, for example,both of the personal stations are brought into a transceivercommunication mode. Thereafter, as shown in FIG. 11, a receiveridentifying code consisting of a terminal number of the personal stationto be called and of the SYS-ID included in the CS-ID registered in theregistered condition memory 31 is prepared, and a transmitteridentifying code which is the PS-ID of the calling personal stationitself is added to the receiver identifying code, so that channelconnection is performed, thereby realizing transceiver communication.

In this way, when a personal station which temporarily belongs toanother base station is registered, it is desirable to delete dataregistered under predetermined condition. Therefore, codes which arethus temporarily registered (e.g., the CS-ID or the like in case of thepersonal station D2) are deleted.

FIG. 12 is a operation flow chart showing a series of processing fordeleting registration data relating to an expanded personal stationregistered in the manner explained above. In this example, when apersonal station is attached to a charger base, registration data storedin the personal station is deleted.

Specifically, when a personal station D2 is attached to a charger base(not shown), a detection signal S1 is inputted into a CPU 21 from anattach/detach detecting circuit 35a and the CPU 21 thereby detects thatthe personal station D2 has been attached to the charger base (step141). The CPU 21 thereby makes determination as to whether or not onlythe flag F3 (transceiver communication) of the terminal station D2stored in the registered condition memory 31 of the personal station D2is permitted (Step 142). Then, if only the flag F3 is thus permitted, acorresponding CS-ID, terminal number, terminal condition and groupterminal number are deleted (step 143).

The above steps also apply to the case where the personal station B1 isattached to the charger base (not shown). In this case, the terminalnumber of the personal station D2 in the group terminal numbers isdeleted. Further, a link with the base station A1 is formed, and theterminal number, PS-ID, and terminal condition of the personal station(e.g., the personal station D2) in which only the flag F3 of theterminal condition in the terminal data memory 9 of the base station A1is permitted.

It is possible to make an arrangement such that registered personalstation data is deleted when the personal station detects whether or nota CS-ID stored in the ID memory 32 has been received. Such anarrangement will be realized if the processing of the above step 141 ischanged to "Is the CS-ID stored in the ID memory 32 has been received?".

FIG. 13 is a flow chart showing another operation of processing fordeleting data relating to an expanded personal station which has alreadybeen registered. In this example, data relating to the expanded personalstation is deleted on the basis of key operation. As this kind ofdeletion method, there are two methods as follows. Since basicoperations are common to both of the methods, these two methods will beexplained with reference to the same figure.

(a) A personal station is brought into a registration mode again, anddial keys 30m of the key input unit 30 are operated so as to input, forexample, "###" thereby inputting a terminal number of a personal stationwhose registration data should be deleted (step 151).

Thereafter, when a set key 30h is pressed down and an instruction ofdeletion is confirmed (step 152), the CPU 21 and the CPPU 22 form aregistration data deletion message, thereby to form a link with thepersonal station designated by the inputted terminal number (step 153).

Then, registration data (a CS-ID, a terminal number, terminal condition,and a group terminal number) stored in a registered condition memory 31of the personal station whose registration data should be deleted isdeleted, and further, the terminal number of the personal station whoseregistration data should be deleted and which is stored in theregistered condition memory 31 of the original personal station itselfis deleted (step 154).

(b) The base station is brought again into a registration mode, andnumerical keys 8d of the key input unit 8 are operated so as to input,for example, "###" thereby inputting a terminal number of a personalstation whose registration data should be deleted (step 151).

Thereafter, a set key 8b is pressed down and an instruction of deletionis confirmed (step 152). Then, the CPU 1 and the CPPU 2 form aregistration data deletion message, thereby to form a link with thepersonal station designated by the inputted terminal number (step 153).

Then, registration data (a CS-ID, a terminal number, terminal condition,and a group terminal number) stored in a registered condition memory 31of the personal station whose registration data should be deleted isdeleted, and further, the terminal number of the personal station whoseregistration data should be deleted and which is stored in theregistered condition memory 31 of the base station is deleted (step154).

FIG. 14 is an operation flow chart showing another example of processingfor deleting registration data registered in a personal station of anexpanded personal station D2. In this example, registration data isdeleted after a predetermined time.

Specifically, the CPU 21 starts counting by a timer 21c of the personalstation when a personal station is registered into a base station. Then,it is determined as to whether or not a predetermined time has passed,i.e., 24 hours have passed (step 161). If the predetermined time haspassed, determination is made as to whether or not communication isbeing made. Then, if communication is not being made, registration data(a CD-ID, a terminal number, terminal condition, and a group terminalnumber) stored in the registered condition memory 31 of the registeredpersonal station is deleted (step 162). Specifically, when communicationis being made on the basis of temporarily registration data,registration data is deleted after communication.

Although determination as to whether or not a predetermined time haspassed from the time of registration in step 161, it is possible todelete registration data of the personal station D2 by deletingregistration data when date is updated, depending on whether or not datais changed in response to an output from the time keeper 21d. Thisstructure is convenient when used for leisure purposes.

In the structure as stated above, for example, to enable transceivercommunication between a personal station B1 or B2 registered in a basestation A1 of a radio communication set T1 and a personal station (forexample, D2) registered in a base station C1 of another radiocommunication set T2, the personal station D2 is registered in the basestation A1 (where only the transceiver communication function ispermitted). Further, even when the personal station D2 uses the basestation A1 to perform outside line transmission in this state, theconnection can be controlled under registered condition.

Therefore, undesirable connection to an outside line through the basestation A1 of another radio communication set T1 can be prevented, sothat it is advantageously possible to previously prevent unreasonablecosts from being consumed for the base station A1. The same advantagecan be obtained when extension transmission from the personal station D2is performed, and therefore, a personal station D2 of another radiocommunication set T2 does not undesirably intervene into extensioncommunication between personal stations B1 and B2 of the same radiocommunication set T1, so that unguarded tapping of communication can beprevented. In addition, since registration of service condition ispermitted, depending on determination as to whether recitation numberscomply with each other, registration of service condition into the basestation A1 of the personal station D2 can be prevented from taking placedue to some unexpected reasons, and the safety of managing the systemcan be improved.

In addition, when transceiver communication is performed, registrationdata (the CS-ID and the like of the base station A1) stored in theregistered condition memory 31 of an expanded personal station D2 isarranged so as to disappear on condition of end of communication, keyinput operation, or changes in a predetermined time and date and hour.In this manner, it is possible to make the right of transceivercommunication between personal stations B1 and B2, which is registeredin the base station A1 and is temporarily granted to the personalstation D2, rapidly disappear.

EMBODIMENT 2

To carry out transceiver communication as explained above, it isrequired as a condition that personal stations must be registered in thesame base station (i.e., personal stations must have a CS-ID of the samebase station).

The second embodiments thus enables so-called transceiver communication,and shows a method of registering dummy base station identification data(i.e., the CS-ID stated above or only the SYS-ID) into a desiredpersonal station. In this embodiment, the schematic structure of theradio communication system and the schematic structures of the basestation and the personal station are the same as those shown in FIGS. 1to 5. Therefore, these figures will be used to explain this embodiment.

Further, operation of this kind of radio communication system will beexplained with reference to a flow chart shown in FIG. 15.

In this case, after a user presses down a function key 8a of the keyinput unit 8 to bring the base station (A1) into a dummy coderegistration mode, request for a dummy ID is selected by a set key 8b(step 171). In response to the dummy ID, the CPU 1 prepares a connectionrequest and dummy ID request message data, and sends the request and thedata to a communication network from a network interface 5 through acommunication line.

Then, in the network side, an unused dummy CS-ID (SYS-ID) is searchedfor in step 181. If an unused dummy CS-ID (SYS-ID) exists, the dummyCS-ID (SYS-ID) is sent to the base station which requests the dummyCS-ID (step 182). The base station receives a dummy CS-ID sent from thenetwork side, and stores the dummy SYS-ID into a RAM 1b (step 172).

Further, a message suggesting an input of a cipher number and the numberof personal stations whose dummy CS-IDs are to be registered isdisplayed on the display of the base station. In response to themessage, numerical keys 8d of the key input unit 8 are pressed down andthe cipher number and the number of personal stations are inputted(steps 173 and 174) and stored into a RAM 1b. In this state, terminalnumbers corresponding in number to the inputted number of personalstations are prepared and are stored into the RAM 1b.

In the next, a function key 30f of the key input unit 30 of the personalstation (B1) whose dummy code should be registered is operated therebyto bring the base station into a dummy code registration mode, and then,a message suggesting an input of a cipher number is displayed on thedisplay 33a of the display unit 33. When numerical keys 30m are operatedand a cipher number is inputted in response to the message, the ciphernumber is stored into the RAM 21b (step 191).

When registration keys 8b of the key input unit 8 of the base station isthen operated, the CPU 1 prepares a dummy code registration requestmessage with using the cipher number stored in the RAM 1b, asidentification data, like registration operation of the firstembodiment. Then, the dummy code registration request message isoutputted to a personal station (step 174).

A personal station receives the dummy code registration request message,and confirms the cipher number included in the identification and thecipher number stored in the RAM 21b. When recognition is completed, alink is formed (step 192).

Further, a predetermined terminal number is selected from terminalnumbers stored in the RAM 1b of the base station A1, and then, a dummyID, a terminal number, and another terminal number (i.e., a groupterminal number) are sent (step 175).

A personal station receives the dummy ID, terminal number, and groupterminal number, and stores then into the registered condition memory 31(step 193). Next, in the base station A1, whether or not a deletion key8c of the key input unit 8 is pressed down is determined (step 176). Ifthe deletion key 8c is pressed down, the step goes to an end. If thedeletion key 8c is not pressed down, a link with the next personalstation (D2) is formed, and steps 174, 191, 174, 175, 192, and 193 arecarried out sequentially in this order, thereby achieving registration.

In this manner, if a dummy ID is registered into a plurality of personalstations from the base station, transceiver communication betweenpersonal stations is enabled by the dummy ID. Specifically, for example,when transceiver communication should be made between a personal stationB1 and a personal station D2, both of the personal stations are broughtinto a transceiver communication mode. Next, which CS-ID of the CS-IDs(or SYS-IDs) stored in the ID memory 32 or the registered conditionmemory 31 should be used is selected. When a terminal number which auser would like to call is designated by one of the personal stations,identification data is prepared on the basis of the selected CS-ID andthe terminal number, and channel connection is attained in apredetermined procedure, thereby realizing transceiver communication.

In addition, explanation of this second embodiment has been made to amethod of registering a dummy ID (CS-ID into a plurality of personalstations which permit transceiver communication. However, the presentinvention is not limited to this method. For example, ID memories eachstoring a dummy ID, a terminal number, and a group terminal number maybe provided in the personal stations such that these ID memories aredetachable therefrom, independently from the ID memories respectivelyincluded in the terminals. These ID memories are respectively attachedto the personal stations, thereby making it possible to directlyregister the dummy ID.

FIG. 16 shows a schematic structure of a personal station to which adetachable ID memory can be attached. Note that the same portions asthose in FIG. 5 are denoted by the same references.

In this case, the personal station is constructed such that an ID memory20 can be connected to the CPU 21 through an interface 19. The ID memory20 has, for example, a card-like shape as shown in FIG. 17. Other thanthe one memory having a card-like shape, a memory having a chip-like orcassette-like shape may be used.

At least a dummy CS-ID (or SYS-ID), the terminal number of a personalstation, and the terminal numbers (or group terminal numbers) of otherpersonal stations are stored in the ID memory 20. In addition, variousdata such as telephone numbers of members, cipher numbers, and optionalservice contracts may be stored. Further, a plurality of such IDmemories 20 having the same CS-ID and the likes may be manufactured. Auser buys such ID memories 20 and attaches them to personal stationswhich the user would like to use for transceiver communication, therebyenabling transceiver communication.

FIG. 17 shows a state in which an ID memory 20 is being attached to apersonal station. If only ID memories 20 which store dummy CS-IDs andthe likes are attached to a plurality of personal stations which a userwould like to use for transceiver communication at a user's destinationof a trip or the like, the same dummy CS-ID can be registered into thesepersonal stations. In this manner, it is possible to easily realizedirect communication between personal stations, i.e., so-calledtransceiver communication.

In addition, the present invention is not limited to the aboveembodiments, but may be modified and changed without deriving from thesubject matter of the invention. For example, in the first embodiment, aCS-ID and the like of a base station are set into an expanded personalstation by performing registration into another base station. Otherwise,a CS-ID and the like may be set from a personal station into which aCS-ID of a base station has been registered. In this case, since a PS-IDof an expanded personal station is not registered into a base stationwhich has a CS-ID set in an expanded personal station, only transceivercommunication can be achieved.

The registration method in the above case is basically similar to thefirst embodiment (i.e., when registration is performed to a basestation). As shown in FIG. 18, a personal station to be expanded and apersonal station to expand are brought into a registration mode (steps200 and 210), and cipher numbers are respectively inputted into thestations (steps 201 and 211). Further, in the side of a personal stationto be registered, a terminal number to register is inputted (step 202),and a registration request from the personal station to register iswaited.

Next, like in the above first embodiment, a registration request messageusing identification data as a cipher number is sent from the personalstation to register (step 212). The personal station to be registeredreceives the registration request message (step 203), and a recitationnumber is extracted from the message. Confirmation as to whether thiscipher number complies with the cipher number inputted in the step 201(step 204). If these cipher numbers comply with each other, the CS-IDregistered in the personal station to be expanded, the terminal number(or group terminal number) of itself, and the terminal number of thepersonal station to register, which is inputted in step 202, are sent tothe personal station to expand (step 205). The personal station toregister receives these numbers and stores then into a registeredcondition memory 31 (step 213). Further, the personal station toregister sends a PS-ID of itself to the personal station to beregistered (step 214). The personal station to be expanded receives thePS-ID of the personal station to register and stores the PS-ID into theregistered condition memory 31 (step 206).

Registration operation is thereby completed. In this manner, the CS-ID(SYS-ID) of the same base station and identification data of the otherpersonal stations are stored. With use of the identification data andidentification code of FIG. 11, transceiver communication is enabled.

In addition, if outside line communication is requested from thepersonal station to expand with use of a newly registered CS-ID,communication can be attained since the PS-ID of a personal station toexpand is not registered into a base station and therefore, a connectionwith a base station cannot be achieved.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, representative devices, andillustrated examples shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. A method of registering a terminal in a basestation of a radio communication system, the radio communication systemcomprising a base station having a system code, and a plurality ofterminals, each of said plurality of terminals having a terminal code,said method including steps executed in the base station as well assteps executed in a registering terminal, said method comprising thesteps of:a) transmitting the system code from the base station to theregistering terminal; b) receiving the base station system code at theregistering terminal; c) registering the system code in the registeringterminal; d) transmitting the terminal code from the registeringterminal; e) receiving the terminal code at the base station; and f)registering the terminal code in the base station in conjunction withdata to be transmitted in a peer-to-peer mode; wherein the registeringterminal utilizes the registered system code to communicate inpeer-to-peer mode with another terminal having substantially the samesystem code registered therein.
 2. A method according to claim 1,wherein said system code registered in the registering terminal isdeleted by completing communication in peer-to-peer mode.
 3. A methodaccording to claim 1, wherein said system code registered in theregistering terminal is deleted when it is determined that theregistering terminal is placed on a charger base for charging theterminal.
 4. A method according to claim 1, wherein said system coderegistered in the registering terminal is deleted by an operation fromthe base station or another terminal when communication in peer-to-peermode is completed.
 5. A method according to claim 1, wherein said systemcode registered in the registering terminal is deleted after apredetermined quantity of time has elapsed or when a date is changed. 6.A method of registering a terminal in a base station of a radiocommunication system, the radio communication system comprising a basestation having a system code and a plurality of terminals, each of saidplurality of terminals having a terminal code, said method includingsteps executed in the base station as well as steps executed in aregistering terminal, said method comprising the steps of:a)transmitting cipher data provided by a user from the registeringterminal to the base station; b) receiving the cipher data from theregistering terminal at the base station; c) transmitting, when thecipher data from the registering terminal coincides with cipher data ofthe base station, a system code from the base station to the registeringterminal; d) receiving the system code from the base station at theregistering terminal; e) registering the system code in the registeringterminal; f) transmitting the terminal code of the registering terminalto the base station; g) receiving the terminal code from the registeringterminal in the base station; and h) registering the received terminalcode in conjunction with data to be transmitted in peer-to-peer mode;wherein the registering terminal utilizes the registered system code tocommunicate in peer-to-peer mode with another terminal havingsubstantially the same system code registered therein.
 7. In a radiocommunication system comprising a plurality of terminals each having acorresponding terminal code, and a base station having a system code anda registration mode in which at least one of the plurality of terminalsis registered thereto, at least one of the plurality of terminals to beregistered in said base station, so as to enable communication inpeer-to-peer mode with another terminal registered in said base station,sending a corresponding terminal code to the base station, said basestation comprising:instruction means for providing an instruction signalto set a registration mode; registration mode setting means for settingthe registration mode substantially subsequent to receipt of theinstruction signal; sending means for, when the registration mode is setby said instruction means, sending the system code to one of theplurality of terminals to be registered; receiving means for receiving acorresponding terminal code provided by the terminal to be registered;and registering means for registering the terminal code received by saidreceiving means together with data which enables the terminal beingregistered to communicate in peer-to-peer mode with another terminalregistered in said base station, and which data inhibits the terminalhaving the registered terminal code from communication via said basestation.
 8. A radio communication system according to claim 7, furthercomprising:means for instructing deletion of registration data relatingto the terminal; and first deleting means for deleting registration datarelating to the terminal when deletion of registration data is requestedby the instructing means.
 9. A radio communication system according toclaim 7, further comprising;second deleting means for deletingregistration data relating to the terminal after a predeterminedquantity of time has elapsed or when date is changed.
 10. In a radiocommunication system comprising a plurality of terminals each having acorresponding terminal code, and a base station having a system code,cipher data, and a registration mode in which at least one of theplurality of terminals is to be registered thereto, at least one of theplurality of terminals to be registered in said base station, so as toenable communication in peer-to-peer mode with another terminalregistered in said base station, sending cipher data to the base stationwhich is substantially the same as the cipher data of the base station,said base station comprising:instruction means for providing aninstruction signal to set a registration mode; registration mode settingmeans for setting the registration mode substantially subsequent toreceipt of the instruction signal; first receiving means for receivingcipher data provided by a terminal to be registered; sending means for,when the cipher data received by said first receiving meanssubstantially coincides with the cipher data of said base station,sending the system code to the terminal to be registered; secondreceiving means for receiving a terminal code, which the terminal to beregistered provides in response to the system code sent by said sendingmeans, from the terminal to be registered; and registering means forregistering the terminal code received by said second receiving meanstogether with data for allowing the terminal to be registered tocommunicate in peer-to-peer mode with another terminal registered insaid base station.
 11. In a radio communication system comprising a basestation and a plurality of terminals, said base station comprising:firstmemory means for storing a system code used to communicate via the basestation and a false system code used to communicate in peer-to-peer modewhich does not communicate via the base station; and false system codesending means for sending the false system code stored in said firstmemory means upon request of a user; and wherein each of said pluralityof terminals comprises: second memory means for receiving and storingthe false system code sent from said base station; and communicatingmeans for communicating with a terminal having substantially the samefalse system code stored therein in peer-to-peer mode by using the falsesystem code stored in said second memory means.
 12. A radiocommunication system according to claim 11, wherein said base stationhas means for obtaining the false system code from outside, and meansfor storing the false system code obtained by the obtaining means withinsaid first memory means.